Climate-based broccoli planting guide for Montrose, Colorado

When to Plant Broccoli in Montrose: Timing and Maturity Guide

Broccoli is usually straightforward to fit into the season in Montrose. Gardeners typically get more value from steady growth and timing than from worrying about whether the crop will finish.

Typical Planting Window

Excellent fit in this climate

Use the planting dates below for broccoli in Montrose.

Start indoors April 1
Typical planting window May 6 – May 20
Method Transplant
Typical days to maturity 60–75

Gardeners usually start indoors around April 1 and plant outdoors from about May 6. Most varieties need about 60–75 days to reach maturity once they are in the garden.

Broccoli is usually easy to fit into the season in Montrose, and the real payoff is having enough room to size the crop properly and harvest at the stage you actually want.

The climate usually makes this crop possible without strain, but the difference between an average result and a strong one still comes from steady growth and harvesting at the right stage.

Best local strategy: Take advantage of the margin by managing for even sizing and a clean finish, not by getting casual about timing.

Can Broccoli Mature in Montrose?

Growing degree days measure how much useful warmth typically accumulates during the season. For broccoli, this helps estimate whether local heat accumulation is usually enough for the crop to reach maturity on time.

Available GDD (base 40) 2777
Typical crop GDD target 900
Heat margin +1877

From the usual planting window, Montrose typically provides about 2777 growing degree days for broccoli. With a typical crop target of 900, that leaves a heat margin of +1877. That large heat margin means the crop usually has no trouble reaching maturity here. In practice, planting timing mostly affects how comfortably the crop sizes up and when harvest is ready, not whether the crop can finish.

GDD Checkpoints for Montrose

If planting later than usual, this table shows how much growing degree day heat is still available from each point in the season. For broccoli, it is most useful for judging how much freedom you still have to plant for quality, finish, and harvest goals as the season moves along.

Checkpoint Remaining GDD Heat margin Fit vs typical target
Apr 15 3008 +2108 Comfortable
May 1 2980 +2080 Comfortable
May 15 2886 +1986 Comfortable
Jun 1 2681 +1781 Comfortable
Jun 15 2440 +1540 Comfortable
Jul 1 2090 +1190 Comfortable

Best Broccoli Varieties for Montrose

The season in Montrose usually supports most broccoli varieties comfortably, which means the more useful decision is what kind of crop you want rather than simply how fast it finishes.

Varieties that often fit well here include:

Variety class Typical days to maturity Typical GDD need Local fit
Very early 55–60 750 Good fit
Early 60–68 850 Good fit
Mid-season 68–78 950 Good fit
Late 78–90 1050 Good fit

Main risk: When this crop disappoints here, the problem is usually practical rather than climatic. Timing, steady growth, and harvest stage matter more than season length.

How Frost Affects Broccoli in Montrose

Montrose usually has about 134 frost-free days, with a typical last spring frost around May 20 and a typical first fall frost around October 1.

Typical last spring frost May 20
Typical first fall frost October 1
Typical frost-free days 134
Minimum safe temperature 28°F / -2 °C

Broccoli is generally lightly frost tolerant and temperatures below about 28°F ( -2 °C) can slow growth or damage plants.

Broccoli is usually tolerant enough of cool conditions that light frost is not the main concern. The more useful question is how early planting affects establishment and overall crop quality.

When this crop disappoints in Montrose, the issue is usually management rather than climate fit. Timing, consistency, and harvest decisions matter more than season length.

In Montrose, the local season usually gives broccoli plenty of breathing room when planting happens around May 13. Local gardens do not all warm and cool at the same pace. For a better local margin, gardeners usually do best in south-facing walls, sheltered gardens, raised beds, and sunnier urban lots. Cooler spots like low spots, exposed sites, and shadier yards often make timing tighter. For broccoli, the best local sites often help the crop get moving earlier and make timing a little more forgiving.

Related crops

Related crops worth comparing for the same city:

For a broader local overview, see the Montrose planting guide. You can also use the Growing Degree Day Planner to test planting dates and crop timing.